3 ms·

Susceptor

peter_d_sherman 6y ago
>"A susceptor is a material used for its ability to absorb electromagnetic energy and convert it to heat (which is sometimes designed to be re-emitted as infrared thermal radiation). The electromagnetic energy is typically radiofrequency or microwave radiation used in industrial heating processes, and also in microwave cooking. The name is derived from susceptance, an electrical property of materials that measures their tendency to convert electromagnetic energy to heat.[1]" [...] >"In microwave cooking, susceptors are built into paper packaging of certain foods, where they absorb microwaves which penetrate the packaging. This process raises the susceptor patch temperature to levels where it may then heat food by conduction or by infrared radiation. Conduction heating occurs with good thermal contact between the susceptor and food. Because of the lower temperatures there is less browning, but more than if there were no susceptor at all. If there is an air gap (or at least, poor thermal contact) between the susceptor and food, the susceptor will heat to a much higher temperature (due to its smaller effective heat capacity when in poor contact with food), and at these higher temperatures, will radiate strongly in the infrared. This infrared radiation then shines onto the food below or next to the susceptor, causing a "broiling" type effect (high skin heating) due to lower ability of infrared to penetrate foods, vs. microwaves. Conversion of some microwave energy to infrared is particularly useful for foods which require a large amount of crust-browning from infrared, such as frozen pies. Design and use Susceptors are usually made of metallised film, ceramics or metals (such as aluminium flakes)." [...] >"External links "Susceptor heating" on commercial website Susceptor heating film on fast food package with carbon-based coatings"
- peter_d_sherman 6y ago
  PDS: Let's parse this a bit better... in English (you know, like in the movie Pulp Fiction: "English, do you speak it?" <g>) To do this, first let's get rid of the fancy, not really necessary, somewhat misleading language constructs... Susceptor = Transducer There! That's better! That's because a "susceptor" IS a transducer -- at least as far as Microwave radiation goes... Here, for reference: https://en.wikipedia.org/wiki/Transducer https://en.wikipedia.org/wiki/Transducer >"A transducer is a device that converts energy from one form to another." Microwave = Energy, Heat = Energy, if a Susceptor converts microwave energy to heat energy, then by definition it is a transducer. (That or Wikipedia is wrong... and we all know that that never happens...<g>) OK, so now that we know that a Susceptor is really a Transducer, what next? Well, here's the thing... If you read the last line, it said that Susceptors, er, Microwave Transducers, can apparently be made with "carbon-based coatings". Why is that interesting or important? Well, consider the following... If you put metal into a microwave... the metal acts as a transducer, but no so much for heat, so much as electricity, high voltage electricty! That metal will turn that microwave into high voltage electricity sooner than quick! That's why metal objects -- should not be placed in microwave ovens... But now, here's the thing! Carbon (at least in its common forms, like charcoal and graphite (note we are not talking about graphene here!)) is a semiconductor. In other words, it's sort of electrically conductive, and it sort of isn't! It's sort of the halfway point between a non-conductor and metal! And here we see that apparently it could be used in a microwave, to generate heat! So now, with all of that background... I have to ask the following set of questions: 1) What's the exact relationship between heat, electricity, and microwaves? 2) How does that relationship vary by the underlying material placed in a microwave, specifically by the electrical conductivity of the underlying material? 3) Electrical transistors can be made; we know all about them; they are commonplace; but can microwave transistors, and/or heat transistors be made? And again, if so, what is their exact relationship to the underlying material? I think I read somewhere that they have microwave transistors -- so they probably already exist. But, that doesn't invalidate the other questions... Note To Future Self: Research this phenomena... Also... how does/would frequency of the microwaves, as well as positioning in the microwave cavity (that is, the microwave oven) affect things? And... can other types of transducers (sound, light, other ranges on the EM spectrum) be made for microwaves?

>"A susceptor is a material used for its ability to absorb electromagnetic energy and convert it to heat (which is sometimes designed to be re-emitted as infrared thermal radiation). The electromagnetic energy is typically radiofrequency or microwave radiation used in industrial heating processes, and also in microwave cooking. The name is derived from susceptance, an electrical property of materials that measures their tendency to convert electromagnetic energy to heat.[1]" [...] >"In microwave cooking, susceptors are built into paper packaging of certain foods, where they absorb microwaves which penetrate the packaging. This process raises the susceptor patch temperature to levels where it may then heat food by conduction or by infrared radiation. Conduction heating occurs with good thermal contact between the susceptor and food. Because of the lower temperatures there is less browning, but more than if there were no susceptor at all. If there is an air gap (or at least, poor thermal contact) between the susceptor and food, the susceptor will heat to a much higher temperature (due to its smaller effective heat capacity when in poor contact with food), and at these higher temperatures, will radiate strongly in the infrared. This infrared radiation then shines onto the food below or next to the susceptor, causing a "broiling" type effect (high skin heating) due to lower ability of infrared to penetrate foods, vs. microwaves. Conversion of some microwave energy to infrared is particularly useful for foods which require a large amount of crust-browning from infrared, such as frozen pies. Design and use Susceptors are usually made of metallised film, ceramics or metals (such as aluminium flakes)." [...] >"External links "Susceptor heating" on commercial website Susceptor heating film on fast food package with carbon-based coatings"

peter_d_sherman 6y ago
PDS: Let's parse this a bit better... in English (you know, like in the movie Pulp Fiction: "English, do you speak it?" <g>) To do this, first let's get rid of the fancy, not really necessary, somewhat misleading language constructs... Susceptor = Transducer There! That's better! That's because a "susceptor" IS a transducer -- at least as far as Microwave radiation goes... Here, for reference: https://en.wikipedia.org/wiki/Transducer https://en.wikipedia.org/wiki/Transducer >"A transducer is a device that converts energy from one form to another." Microwave = Energy, Heat = Energy, if a Susceptor converts microwave energy to heat energy, then by definition it is a transducer. (That or Wikipedia is wrong... and we all know that that never happens...<g>) OK, so now that we know that a Susceptor is really a Transducer, what next? Well, here's the thing... If you read the last line, it said that Susceptors, er, Microwave Transducers, can apparently be made with "carbon-based coatings". Why is that interesting or important? Well, consider the following... If you put metal into a microwave... the metal acts as a transducer, but no so much for heat, so much as electricity, high voltage electricty! That metal will turn that microwave into high voltage electricity sooner than quick! That's why metal objects -- should not be placed in microwave ovens... But now, here's the thing! Carbon (at least in its common forms, like charcoal and graphite (note we are not talking about graphene here!)) is a semiconductor. In other words, it's sort of electrically conductive, and it sort of isn't! It's sort of the halfway point between a non-conductor and metal! And here we see that apparently it could be used in a microwave, to generate heat! So now, with all of that background... I have to ask the following set of questions: 1) What's the exact relationship between heat, electricity, and microwaves? 2) How does that relationship vary by the underlying material placed in a microwave, specifically by the electrical conductivity of the underlying material? 3) Electrical transistors can be made; we know all about them; they are commonplace; but can microwave transistors, and/or heat transistors be made? And again, if so, what is their exact relationship to the underlying material? I think I read somewhere that they have microwave transistors -- so they probably already exist. But, that doesn't invalidate the other questions... Note To Future Self: Research this phenomena... Also... how does/would frequency of the microwaves, as well as positioning in the microwave cavity (that is, the microwave oven) affect things? And... can other types of transducers (sound, light, other ranges on the EM spectrum) be made for microwaves?